Find transactions

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond the readOnly/idempotent/openWorld annotations: discloses the cost (three YNAB requests), the operational constraint (at most a year between dates), output ordering (newest first), the truncation-and-remedy behavior, the amount sign convention, and a prompt-injection caution about payee/memo text. This is exactly the extra behavioral context annotations do not carry.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Purpose and primary use cases are front-loaded in the first two sentences, and every remaining clause carries operational value (request cost, date cap, ordering, injection warning). It is dense and slightly packed, but there is little wasted text.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, return values need not be explained, and the annotations cover the safety profile. The description nonetheless anticipates the tricky cases an agent will hit - truncation, the one-year window, amount sign - so nothing needed to call it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so parameters are already documented and baseline is 3. The description adds meaning beyond the schema by pairing `truncated` with the remediation (narrow dates or supply amount) and restating the date-span cap and negative-for-spending convention, which reinforces how to set amount/date parameters.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Find transactions') and enumerates the filter dimensions (date, amount, account, category, payee), plus scope 'categorised or not'. It explicitly distinguishes itself from suggest_categories, so an agent can route between them without opening schemas.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives concrete use cases ('match a receipt or a bank line with its transaction', 'see what a category was spent on') and names the alternative, suggest_categories, with the exact condition that selects it ('only lists what still waits for a category'). When-to-use and when-to-prefer-a-sibling are both present.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.